The invention relates to a method for outputting navigation instructions in a motor vehicle which has a navigation system and a head-up display device suitable for outputting graphical navigation information.
It is known from the state of the art to output navigation instructions in several graphically differently designed steps. It is also known from the state of the art to output driving lane information. However, depending on the embodiment, some of the known display types are still not difficult to be intuitively understood by the respective operator.
Head-up display devices, by which graphical information can be projected by way of the windshield into the driver's field of vision, have in the meantime become increasingly available in modern motor vehicles.
It is an object of the invention to provide a simple method for outputting easily comprehensible navigation instructions to the driver of a motor vehicle.
This and other objects are achieved by a method according to the invention, in which graphical navigation instructions are output in at least three instruction categories, which categories differ significantly with respect to the extent of graphical details of the respective navigation instruction. Which instruction category is selected for the output of a navigation instruction to be output is at least a function of the distance of the motor vehicle to an action point of the navigation maneuver announced by the navigation instruction, possibly the traveled road type. The following applies, for example, to highways when three categories are used: Instruction category 1 on the last 400 meters before the action point of the announced turn-off maneuver; instruction category 2 in the case of distances to the action point between 2,000 meters and 400 meters; instruction category 3 in the case of distances to the action point of more than 2,000 meters.
Navigation instructions of that instruction category (in the following called the first instruction category), which is selected for short distances (in the above example, on highways, thus a distance of less than 400 meters from the action point) comprise a perspective lane-exact display of a map section relevant to the navigation maneuver in the head-up display device. In the head-up display device, a first driving line proposed by the navigation system is depicted in the map section in a lane-exact manner by way of a first graphical line object (i.e. in the shape of a first graphical line object). In addition, a second driving line proposed by the navigation system as an alternative is depicted in the map section in a lane-exact manner by a second graphical line object, which differs from the first line object at least with respect to its graphical object fill. The action point is graphically marked in the map section by an action point marker arranged along the first line object. The current distance between the motor vehicle and the action point is graphically marked in the map section by way of a distance marker arranged along the first line object in line with position changes of the motor vehicle.
The graphical navigation instructions of the first instruction category thereby provide the driver in a simple and low-diversion manner with an easily interpretable information spectrum that is clearly improved in comparison to the state of the art.
The distance marker for marking the current distance between the motor vehicle and the action point can be generated particularly advantageously in that, below the action point marker, the first line object has a first area essentially adjacent to the action point marker and having a first graphical object fill, that it further has a second area adjacent to this first area, which second area extends to the lower end of the line object and has a second graphical object fill, and that the boundary between the first area and the second area is displaced with an increasing distance in the direction of the action point marker. In other words, the distance marker for marking the current distance between the motor vehicle and the action point consists of the fact that, at the location of the first line object, which corresponds to the current position of the motor vehicle, a transition takes place from a first graphical object fill of the first line object to a second graphical object fill of the first line object. In this manner, a display form, which is known from the state of the art, is elegantly modified as a separate distance bar which “gradually erases itself” as the distance decreases and is taken over into the overall display on the basis of the perspective road map.
According to a preferred embodiment of the present invention, even navigation instructions of a second instruction category, which is selected for medium distances, contain lane information. The latter information is visualized by a graphical display of the driving lanes available in the current position of the motor vehicle in its current driving direction. This graphical display is kept in an extreme landscape format, essentially constructed as a horizontal strip, and is arranged at the lower edge of the display surface of the head-up display device. The landscape format and the arrangement at the lower edge ensure that the driver will not already be substantially distracted from the traffic situation by this display. He can nevertheless already obtain and follow driving lane instructions. In the case of navigation instructions of the second instruction category, the action point is still relatively far away, which is why the graphical display of the lanes in the second instruction category still ends before the action point.
According to a particularly preferred embodiment of the present invention, that is based on this embodiment, the graphical display of the driving lanes is taken over from the second instruction category as part of the map section into the first instruction category (which is selected for short distances), when, because of a reduction of the distance between the motor vehicle and the action point, a transition takes place from the second instruction category to the first instruction category. Therefore, when, during the display of the navigation instruction of the second instruction category, the driver's view is fixed on the driving lane information strip shown in the landscape format, he can continue to focus on the latter during the transition to the display of the navigation instruction of the first instruction category because the driving lane information strip is taken over into the latter. For this purpose, the driving lane information strip visible in the second instruction category should naturally already be constructed in a graphically particularly suitable manner. It should particularly have a suitable size and provide a suitable perspective display of the driving lanes.
In other words, the navigation instruction of the second instruction category should already contain a section—having a landscape format and limited to an area ahead of the action point—of the map section which subsequently is to be displayed perspectively within the scope of the navigation instruction of the first instruction category.
Again in other words, the map section displayed within the scope of the navigation instruction of the first instruction category graphically “develops” from the driving lane information strip previously displayed within the scope of the navigation instruction of the second instruction category.
The above-mentioned particularly preferred embodiment of the present invention can advantageously be further developed such that the driving lane information of the second instruction category contains driving lane indication objects which had already been advantageously adapted to the display of the first instruction category. In particular, the graphical display of the driving lanes in the second instruction category can be graphically enriched by use of a first driving lane indication object which marks that driving lane on which the first driving line extends that is proposed by the navigation system as well as by use of second driving lane indication object which marks that driving lane on which the second driving line extends that was proposed by the navigation system, in which the second driving lane indication object differs from the first driving lane indication object at least with respect to its graphical object fill. The first driving lane indication object can be replaced by the first line object when, because of a reduction of the distance between the motor vehicle and the action point, a transition takes place from the second instruction category to the first instruction category, and the second driving lane indication object can be replaced by the second line object when, because of a reduction of the distance between the motor vehicle and the action point, a transition takes place from the second instruction category to the first instruction category.
A particularly clear graphical “development” of the map section displayed within the scope of the navigation instruction of the first instruction category from the driving lane information strip previously displayed within the scope of the navigation instruction of the second instruction category is achieved in that the graphical object fill of the first line object corresponds essentially to that of the first driving lane indication object, and in that the graphical object fill of the second line object corresponds essentially to that of the second driving lane indication object. The driver observing the transition will be able to assign mutually corresponding information without any problem.
According to a preferred embodiment of the present invention, the navigation instructions of a third instruction category, which is selected for large distances, contain no driving lane information. It appears to be particularly advantageous to not even output such navigation instructions by way of the head-up display device but by way of a second display unit suitable for the output of graphical navigation instructions. In particular, such navigation instructions of the third instruction category can be output in the instrument cluster of the motor vehicle.
The description of the present invention is based on the fact that lane-accurate map data are present and that, therefore, lane-accurate driving lines can be computed and recommended by the navigation system, and that lane-accurate navigation instructions can be output. It is, however, not assumed in the present description that the position of the motor vehicle is known in a lane-exact manner. It is therefore assumed in the present description that the first and the second driving line proposed by the navigation system are computed independently of the currently traveled driving lane. However, the invention can equally be applied in a case in which the currently traveled driving lane of the motor vehicle is known, and the first and second driving lines are computed on this basis.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.